This invention relates to an arrangement for controlling the pitch of a propeller used on marine diesel motor vessels. More particularly, a propeller pitch controlling arrangement which is operable to a fuel economizer mode whereby the propeller pitch is regulated to obtain optimum performance of the engine under any throttle setting. Typically, propeller pitch controlling arrangements have provided for regulating the pitch of the propeller only in the event of an overload on the engine. One such load monitoring propeller pitch controlling arrangement can be found in U.S. Pat. No. 3,443,587, assigned to the assignee of the present application. A load sensing valve in the previously mentioned patent uses a double acting power cylinder subjected to opposing load sensing and speed control pressures to regulate the propeller pitch. Such an arrangement is not selectively operated nor does it act to maximize fuel efficiency and engine performance; the propeller pitch therefore is varied as a function of a predetermined overload pressure. Still other propeller pitch controlling arrangements have attempted to control the propeller pitch to achieve an efficient use of fuel; however, such applications typically have provided a pitch signal dependent on secondary data such as, for example, exhaust temperature, fuel flow and RPMs. The propeller pitch controlling arrangements which use the above-mentioned secondary data have the disadvantage that the equipment necessary to detect and analyze such secondary data is expensive and a further disadvantage that the pitch controlling signal does not accurately and quickly control the system.